Studies of the role of thiol-disulfide reactions of proteins in physiologically important regulatory processes are proposed and justified on the basis of chemical, biochemical, and biological considerations. Initial studies with the fungus Neurospora crassa show that high oxidized glutathione (GSSG) and protein bound glutathione (PSSG) levels occur in the dormant spores (conidia) relative to the vegetative state (mycelia) and that these differences largely disappear in the first minutes of the conidial germination process which connects these two states. It is proposed that high disulfide levels are important in controlling the properties associated with dormancy and studies to test and elaborate this hypothesis in fungi, bacteria, seeds and other systems with dormant states are in progress. The results of these studies may have important consequences for our understanding of the mechanism by which protein synthesis and other enzymatic processes are regulated in dormant states and activated when dormancy is broken. BIBLIOGRAPHIC REFERENCES: The Glutathione Thiol-Disulfide Status in the Sea Urchin Egg During Fertilization and the First Cell Division Cycle. Robert C. Fahey, Stephen D. Mikolajczyk, G. Patrick Meier, David Epel, and Edward J. Carroll, Jr., Biochem. Biophys. Acta, 437, 445-453 (1976). Biologically Important Thiol-Disulfide Reactions and the Role of Cyst(e)ine in Proteins: An Evolutionary Perspective. Robert C. Fahey, in Protein Cross-linking: Biochemical and Molecular Aspects (Part A), M. Friedman, ed., Plenum, New York, 1977.